材料科学与工艺
材料科學與工藝
재료과학여공예
MATERIAL SCIENCE AND TECHNOLOGY
2015年
2期
19-24
,共6页
章艳%张兴权%左立生%周煜%段士伟%黄志来
章豔%張興權%左立生%週煜%段士偉%黃誌來
장염%장흥권%좌립생%주욱%단사위%황지래
激光喷丸强化%半圆孔件%残余应力%疲劳断口%疲劳寿命
激光噴汍彊化%半圓孔件%殘餘應力%疲勞斷口%疲勞壽命
격광분환강화%반원공건%잔여응력%피로단구%피로수명
laser shot peening%semicircle hole specimen%residual stress%fatigue fracture%fatigue life
为研究激光喷丸强化对7075-T6铝合金半圆孔件疲劳寿命的影响,对激光喷丸与未喷丸的试样进行了对比试验,利用X射线应力仪测定其表面残余应力,并对试样进行疲劳拉伸试验.用扫描电镜观察了两类试样疲劳断口的形貌,并采用数理统计方法对其疲劳寿命进行分析.研究表明:经激光喷丸处理区域,表面存在较大的残余压应力,幅值为310 MPa;未喷丸试样疲劳裂纹条带的宽度为0.7~0.8μm,而喷丸试样疲劳裂纹条带的宽度为0.3~0.4μm,说明喷丸试样裂纹扩展的速度比未喷丸试样慢很多;激光喷丸后半圆孔件的疲劳寿命比未喷丸的疲劳寿命提高了2.8~7.2倍.
為研究激光噴汍彊化對7075-T6鋁閤金半圓孔件疲勞壽命的影響,對激光噴汍與未噴汍的試樣進行瞭對比試驗,利用X射線應力儀測定其錶麵殘餘應力,併對試樣進行疲勞拉伸試驗.用掃描電鏡觀察瞭兩類試樣疲勞斷口的形貌,併採用數理統計方法對其疲勞壽命進行分析.研究錶明:經激光噴汍處理區域,錶麵存在較大的殘餘壓應力,幅值為310 MPa;未噴汍試樣疲勞裂紋條帶的寬度為0.7~0.8μm,而噴汍試樣疲勞裂紋條帶的寬度為0.3~0.4μm,說明噴汍試樣裂紋擴展的速度比未噴汍試樣慢很多;激光噴汍後半圓孔件的疲勞壽命比未噴汍的疲勞壽命提高瞭2.8~7.2倍.
위연구격광분환강화대7075-T6려합금반원공건피로수명적영향,대격광분환여미분환적시양진행료대비시험,이용X사선응력의측정기표면잔여응력,병대시양진행피로랍신시험.용소묘전경관찰료량류시양피로단구적형모,병채용수리통계방법대기피로수명진행분석.연구표명:경격광분환처리구역,표면존재교대적잔여압응력,폭치위310 MPa;미분환시양피로렬문조대적관도위0.7~0.8μm,이분환시양피로렬문조대적관도위0.3~0.4μm,설명분환시양렬문확전적속도비미분환시양만흔다;격광분환후반원공건적피로수명비미분환적피로수명제고료2.8~7.2배.
In order to investigate the effect of laser shot peening on fatigue life of 7075-T6 Al alloy specimen with a semicircle hole, the comparative tests were conducted between the laser?peened specimen and the un?peened specimen. The surface residual stresses were measured with model X-350A of X?ray diffraction stress analyzer and fatigue tests were carried out. The fatigue fracture morphology of two kinds of specimens were observed with the model JSM-7001F of scanning electron microscope, and the fatigue life was comprehensively studied by statistical analysis. The results show that the laser shot peening can induce the residual compressive stress in laser?peened zone, and its magnitude reaches to 310 MPa. The spacing of the fatigue striations in un?peened specimen is roughly 0.7~0.8μm, while the spacing of the fatigue striations in peened specimen is only 0.3~0.4 μm, which indicates that the crack propagation rate of the peened sample is slower than that of the un?peened case. The average fatigue life of the laser?peened specimen is 2.8~7.2 times than that of the un?peened specimen.